<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div {
            width: 100px;
            height: 100px;
            border: 1px solid red;
        }
        #d1{
            /*margin-right: 50px;*/
            /*margin: 10px 20px 30px 40px;*/
            margin-bottom: 20px;
        }
        #d2{
            /*上下相邻两个元素彼此添加外边距，取最大值*/
            margin-top: 20px;
        }
        span {
            border: 1px solid blue;
        }
        #s1 {
            margin-left: 30px;
            margin-right: 20px;
        }
        #s2 {
            /*左右相邻彼此添加外边距，两值相加*/
            margin-left: 20px;
        }
    </style>
</head>
<body>
<span id="s1">span1</span><span id="s2">span2</span>
<div id="d1">div1</div>
<div id="d2">div2</div>

</body>
</html>